Viewing: llapi_pcc_attach.3

.TH LLAPI_PCC_ATTACH 3 2024-08-28 "Lustre User API" "Lustre Library Functions"
.SH NAME
llapi_pcc_attach, llapi_pcc_attach_fid, llapi_pcc_attach_fid_str \- attach a file into PCC
.SH SYNOPSIS
.nf
.B #include <lustre/lustreapi.h>
.PP
.BI "int llapi_pcc_attach(const char *" path ", __u32 " id ,
.BI "                     enum lu_pcc_type " type );
.PP
.BI "int llapi_pcc_attach_fid(const char *" mntpath ", const struct lu_fid *" fid ,
.BI "                         __u32 " id ", enum lu_pcc_type " type );
.PP
.BI "int llapi_pcc_attach_fid_str(const char *" mntpath ", const char *" fidstr ,
.BI "                             __u32 " id ", enum lu_pcc_type " type );
.fi
.SH DESCRIPTION
The function
.BR llapi_pcc_attach() ,
.B llapi_pcc_attach_fid()
and
.B llapi_pcc_attach_fid_str()
tries to attach the file referenced by
.IR path ,
.IR fid ,
or
.IR fidstr
into PCC backend. PCC provides a group of local caches and works in two modes:
RW-PCC enables a read-write cache on the local SSDs of a single client; RO-PCC
provides a read-only cache on the local SSDs of multiple clients. For RW-PCC,
the argument
.I id
is the archive ID of the copytool agent running on this client. By default,
RO-PCC attach ID is setting same with RW-PCC attach ID for a PCC backend if it
is also used as read-only caching. The attach mode is specified by
.I type
argument, which is a
.B enum lu_pcc_type
data structure, which contains the following values:
.nf
.LP
	LU_PCC_NONE
	LU_PCC_READWRITE
	LU_PCC_READONLY
.fi
.TP
LU_PCC_NONE
means that the file is not cached on PCC.
.TP
LU_PCC_READWRITE
means RW-PCC mode.
.TP
LU_PCC_READONLY
means RO-PCC mode.
.SH RETURN VALUES
.B llapi_pcc_attach()
return 0 on success or a negative errno value on failure.
.SH ERRORS
.TP 15
.B -ENOMEM
Insufficient memory to complete operation.
.TP
.B -EFAULT
Memory region is not properly mapped.
.TP
.B -EINVAL
One or more invalid arguments are given.
.TP
.B -EOPNOTSUPP
PCC attach operation is not supported.
.SH AVAILABILITY
.BR llapi_pcc_attach() ,
.B llapi_pcc_attach_fid()
and
.B llapi_pcc_attach_fid_str()
are part of the
.BR lustre (7)
user application interface library since release 2.13.0
.\" Added in commit v2_12_53-113-gf172b11688
.SH SEE ALSO
.BR lustreapi (7)